1. TOTALITY PROBLEM -> undecidable for recursive language.

2. MEMBERSHIP PROBLEM -> Decidable for recursive language.

3. EMPTINESS PROBLEM -> Undecidable for recursive language.

4. REGULARITY PROBLEM -> Undecidable for recursive language.

So, option 2. should be the answer

2. MEMBERSHIP PROBLEM -> Decidable for recursive language.

3. EMPTINESS PROBLEM -> Undecidable for recursive language.

4. REGULARITY PROBLEM -> Undecidable for recursive language.

So, option 2. should be the answer